Core yarn and woven and knitted fabric

ABSTRACT

It is an object of the present invention to provide a core yarn capable of spinning the higher-grade yarn having the higher yarn count from specified lower-grade raw material and the core yarn makes its texture-feeling, strength and extension rate equal to that of natural fibers. The core yarn is formed of spun yarn including the core formed of filament yarn and the sheath formed of staple, and the filament yarn is a monofilament false twist textured yarn.

FIELD OF THE INVENTION

The present invention relates to a core yarn comprising a core and a sheath, particularly a core yarn using an untwisted filament yarn for the core and natural fiber for the sheath and woven and knitted fabrics using this core yarn.

BACKGROUND OF THE INVENTION

Conventionally known is a composite fiber comprising a multifilament yarn of chemical synthetic fiber as a core, which is wrapped around with spun yarn made of natural fiber or chemical synthetic fiber.

The above mentioned spun yarn is a thread in which natural fibers having short fiber-length such as cotton and wool are twisted through conventional spinning process. Filament yarn is a chemical synthetic fiber produced as a continuous long filament yarn through fiber spinning process.

Further, the natural fiber is produced as spun yarn formed of staple fiber aggregate twisted by a ring spinning machine and an air spinning machine. Therefore the natural fiber has lower yarn strength than the filament yarn does at the same yarn count.

When a cotton yarn of a spun yarn is spun, quality (grade: thickness and length of fiber) of cotton to be material is set corresponding to desired yarn count. When a fine yarn count cotton yarn is spun, high-quality fine and long cotton material should be used. And when thick cotton yarn is spun, even low-quality thick and short cotton material can be spun.

Further, known as the above mentioned composite fiber is a core yarn of core-sheath composite fiber formed of a core completely wrapped with a sheath. For example, when a spun yarn such as cotton yarn and wool yarn is spun, a core yarn in which filament yarn of the above mentioned continuous long fiber is inserted as core in a drafting process, or spinning process and the core is wrapped with cotton yarn and wool yarn used as sheath can be spun.

Further as for a spinning machine for manufacturing a corn yarn, already known is an air spinning machine capable of spinning the core yarn in which a core is not twisted and the untwisted core is wrapped around with twisted spun yarn (ref. to, for example, Japanese Patent JP-A-2001-164432).

As for general filament yarn, a multifilament yarn consists of plural pieces of filaments having about 1 to 30 denier per a single fiber which are bundled to form a single yarn-thread. And there also exists a yarn-thread called as a monofilament consisting of a thick single fiber filament having tens to hundreds denier.

And although false twist textured process is performed to provide natural fiber-like subdued shine and crimp to the rigid filament yarn originally having shine, false twist textured process is performed with a draw false twist texturing machine and the like using a large diameter package wound around with the above mentioned multifilament yarn-thread, but monofilament itself is not false twist textured.

Therefore, when false twist textured yarn of monofilament is manufactured, after multifilament yarn is false twist textured, the multifilament-state false twist textured yarn is separated into each pieces to obtain.

Further conventionally published is a method for manufacturing separated yarn by separating from multifilament fiber package to single filament or from the above mentioned multifilament yarn to multifilament yarn having less single yarn number and winding up (For example, Japanese Patent JP-A-H06-116807)

With the core yarn spun using filament yarn as a core and staple fiber as a sheath, no yarn breakage occurs in the spinning process because the core exists, thereby spinning becomes easy. Therefore, spinning is possible even by using lower quality cotton material.

However, even with the core yarn comprising the filament yarn as a core, it is impossible to spin cotton yarn having fine yarn count in the case of thick filament yarn. On the other hand, the-thinner cotton yarn can be spun using the thinner filament yarn, however, it is difficult to spin cotton yarn having desired fine yarn count, because filament yarn is different from cotton yarn in extension rate and strength.

Further, with thin filament yarn used as a core, yarn strength and extension rate are poor and such a sense of superior quality as conventional 100% cotton with fine yarn count has can not be obtained with regard to touch and flexible sensitivity, thereby it is difficult to spin cotton yarn having desired fine yarn count.

And then using with thin and poor strength filament, there is a further problem that filament yarn as a core is separated from spun yarn to cause yarn separation during weaving process and knitting process.

In the case of a ring spinning machine for spinning by entirely twisting the yarn, the core of the core yarn is also twisted and twist torque is left to cause problems of unwinding and threading in the weaving process and the knitting process. Therefore, especially the core yarn using monofilament as a core is not practically utilized with the ring spinning machine.

SUMMARY OF THE INVENTION

The present invention was made to resolve the above-discussed problems and has an object of an illustrative, non-limiting embodiment of the present invention is to provide a core yarn which makes superior quality yarn having finer yarn count spun from specified lower-grade raw material and makes texture-feeling, strength and extension rate the same level of those of natural fibers.

The present invention according to a first aspect solves the above-mentioned objects and is a core yarn is formed of a spun yarn comprising a core formed of filament yarn and sheath formed of staple fiber, wherein said filament yarn consists of single or plural monofilament false twist textured yarn.

Therefore, in the core yarn, since the core having high flexibility and high yarn strength is wrapped with staple fiber, a spun yarn having fine yarn count can be spun.

The invention according to a second aspect is the above mentioned core is formed of an untwisted yarn and wrapped around with staple fiber while staying the untwisted state.

Therefore, since the twist-torque is not left in the core, the core yarn having excellent texture-feeling of softness and smoothness can be span.

The invention according to a third aspect is the above mentioned core is formed of a polyestermonofilament false twist textured yarn.

Therefore, since it is easy to obtain and the most popular yarn for clothes, the core yarn applicable for underwear and outerwear can be spun.

The invention according to a fourth aspect is the thickness rate of said core is preferably not more than approximately 20 to 40% of the whole the core yarn, and rate of said sheath is not less than approximately 80 to 60%.

Therefore, said core is completely covered with the sheath. And yarn-strength of the core yarn is higher than that of the pure spun yarn and with regard to feeling of fabric; the core yarn maintains softness equal to that of the spun yarn.

The invention according to a fifth aspect is the above mentioned staple fiber is cotton, the above mentioned core is a polyester monofilament false twist textured yarn of 20 denier and a cotton yarn having cotton yarn count Ne20 to Ne100 is spun.

Therefore, the core yarn having wide range of yarn count can be spun using a polyester monofilament false twist textured yarn. Fine yarn count core yarn can be spun using single 20 denier polyester monofilament false twist textured yarn, and thick yarn count core yarn can be spun using 2-4 plural 20 denier polyester monofilament false twist textured yarn.

The invention according to a sixth aspect is the core yarn is spun by air spinning machine in which fasciated spun yarn is spun while binding around the untwisted core with sheath fiber.

Therefore, fasciated spun yarn comprising untwisted core wrapped around with staple fiber can be easily spun at high speed.

The invention according to a seventh aspect is woven and knitted fabric woven or knitted using the core yarn according to any one of the first to fifth aspects.

Therefore, woven fabric and knitted fabric can be obtained using the corn yarn which has desired texture-feeling, strength, extension rate spun using lower quality spun materials.

As mentioned above, with the present invention, since the core yarn is configured to comprise polyester monofilament false twist textured yarn having specified thickness as a core, and natural fiber wrapping around the core and bundling together, the obtained cotton yarn with core yarn of fine yarn count has high extension rate, high yarn strength and excellent texture-feeling even though low-grade cotton material is used.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a configuration of a core yarn related to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a core yarn using plural monofilament false twist textured yarn.

FIG. 3 is a schematic diagram of an air spinning machine for spinning the core yarn related to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the core yarn and woven and knitted fabric related to the present invention will be described with reference to FIGS. 1 to 3.

As shown in FIG. 1, the core yarn 1 related to the present invention is a core-sheath composite fiber comprising core 2 and sheath 3. The core 2 is a piece a single filament, or a monofilament and the sheath 3 is spun yarn twisted together with staple fibers. For example, many staple fibers are wound around the above-mentioned core 2 while being twisted. And as shown in FIG. 2, the core yarn 1 is a core-sheath composite fiber comprising core 2 and sheath 3. The core 2 consists of plural monofilament and the sheath 3 is spun yarn twisted together with staple fibers.

Here, preferred embodiment of the air spinning machine for manufacturing the above mentioned core yarn 1 is explained with reference to FIG. 3. In the spinning method of the spinning machine, sliver L is delivered to a draft apparatus DR and drawn into the specified thinness, and then spun yarn is formed by swirling flow from nozzle of the air spinning machine provided in a spinning section Sp. And the spun yarn-thread is sent to the winding up section through nip rollers NR and winding up with package PW.

The above mentioned draft apparatus DR is provided with back roller Rb, third roller Rt, middle roller Rm having apron belt, and front roller Rf, which are arranged in sliver travel direction at specified intervals and respectively consist of a pair of upper and lower rollers. The sliver L fed through a trumpet T, or a guide to insert the sliver L, is drawn into the specified thickness. Rollers are a plural pairs of rollers in which travel speed gradually increases as roller arrangement is located toward downstream. Through a roller draft section comprising these rollers, the object is drawn into the specified thickness and sent to the spinning section Sp.

Although the above mentioned spinning section Sp capable of high speed spinning comprises two-stage air spinning nozzle for generating swirling flow, a spinning section is not specifically limited to this. The spinning section may have a single step spinning nozzle for generating swirling flow and a spinning spindle, further the spinning section may have a single step air spinning nozzle and a twisting section provided with a pair of twisting rollers.

Here, yarn-thread corresponding to the core 2 is introduced from the front roller Rf in upper stream side to substantial central portion of the sliver bundle sent while being drafted.

The above mentioned core 2 is drawn from a yarn feeding package 10 and introduced through feeding roller 20 while being applied with specified yarn tension. In this case, with introduction of the core 2 to substantial central portion of the sliver bundle sent while being drafted, the core 2 is wrapped as a center with spun yarn Y (sheath 3) to produce a core yarn 1 of core-sheath composite fiber.

Since the above mentioned spinning section Sp swivels yarn-thread using the air spinning nozzle, the fed core 2 is not actually twisted but only false-twisted. Therefore, the spun yarn having passed through spinning section Sp becomes fasciated spun yarn (core yarn 1) having a configuration in such that the untwisted core 2 is wrapped and wound around with the spun yarn Y (sheath 3) of staple fiber.

Therefore, twist torque is not left in the yarn-thread. And the outside of the yarn-thread has feeling of fabric (stiffness, softness, and fullness etc.) like cotton spun yarn and can be equally applied to clothing products of a spun yarn made of 100% cotton.

In this embodiment of the present invention, polyester monofilament false twist textured yarn is employed for the above mentioned core 2. Since false twist textured yarn is superior in crimping property and has compatibility, even if the core yarn 1 is produced by wrapping around the above mentioned polyester monofilament false twist textured yarn with cotton staple fiber, it can have similar feeling of fabric with the cotton yarn made of 100% cotton. Further, since yarn strength of the core yarn 1 increase because of strength of the core, spun yarn like core yarn having strength and fine yarn count can be spun by using low-quality cotton material.

Further, thickness rate of the core 2 is preferably not more than approximately 20 to 40% of the whole core yarn 1 so as to be completely wrapped with the sheath 3. And rate of the above mentioned sheath 3 is not less than approximately 80 to 60%, so that the core 2 is completely covered with the sheath. Therefore, because of presence of the core 2, yarn strength of the core yarn 1 is higher than that of the pure spun yarn Y and with regard to feeling of fabric, the core yarn maintains softness equal to that of the spun yarn Y.

Next, polyester monofilament false twist textured yarn manufacturing method will be described.

As mentioned above, after the multifilament yarn-thread formed of bundle of multiple pieces of monofilament yarn-thread is integrally false-twisted with the false twisting machine, the multifilament is separated into all pieces to obtain monofilament false twist textured yarn.

Further, with a splitting machine capable of separating the multifilament yarn-thread into all pieces and winding up them immediately after false-twist texturing process, plural monofilament false twist textured yarns can be continuously produced.

For example, explained is an embodiment of false-twist texturing a multifilament of 240 denier formed by bundling twelve pieces of monofilaments of 20 denier. This monofilament is for example polyester and in the case of POY of undrawn yarn, it is fed to the false-twist texturing machine while being drawn, and in the case of FDY of drawn yarn, it is fed directly to the false-twist texturing machine, and they are false-twisted while being unwinded in untwisted state. And yarn-thread having been false-twist texturized is separated into 12 pieces of polyester monofilament false twist textured yarn respectively having 20 denier and they are wound up to twelve pieces of monofilament bobbins. Further, yarn-thread having been false-twist texturized is separated into 6 pieces to obtain double polyester monofilament false twist textured yarn, and separated into 4 pieces to obtain triple polyester monofilament false twist textured yarn respectively having each 20 denier yarn size.

After the above mentioned false twist texturing process, the obtained polyester monofilament false twist textured yarn is supplied as the core and the core yarn 1 is spun with the above mentioned air spinning machine.

Further, in above mentioned spinning process, the core yarn having cotton yarn count of Ne20 to Ne100 which comprises the core of the polyester monofilament false twist textured yarn of 20 denier and the sheath of cotton can be spun. For example, with regard to core-sheath ratio, the percentage of the core 2 of 20 denier single monofilament false twist textured yarn is about 22% with cotton yarn count e.g. Ne60 and about 30% with cotton yarn count Ne80 and about 38% with cotton yarn count Ne100.

And the percentage of the core 2 of 20 denier triple monofilament false twist textured yarn is about 22% with cotton yarn count Ne20. Anyway suitable monofilament thread number is chosen, and core yarns of a predetermined size of yarn count can be produced. So the thickness rate of said core should be preferably not more than approximately 20 to 40% of the whole the core yarn, and rate of said sheath is not less than approximately 80 to 60%.

Thus, since in the core yarn 1 related the present invention, the core 2 is a untwisted yarn and wrapped around with the sheath 3 (short fiber-length cotton fiber) in the untwisted state and spun, twist torque is not left in the core and the excellent core yarn having soft and smooth feeling of can be spun. Further since a core and sheath bundle condition is excellent because of the core of false twist textured yarn, the yarn is not separated and preferable.

Furthermore, since high-grade yarns having higher yarn count can be spun from the specified lower-grade materials, it is economically effective. And this effectively increases the coverage of cotton material use.

For example, with California cotton of middle-grade cotton, it has been possible to spin Ne40 cotton yarn count has been and impossible to spin the higher cotton yarn count (e.g. Ne60 or Ne80). This is because the number of fibers required for comprising the yarn-thread is not satisfied. However with the core yarn using polyester monofilament false twist textured yarn of 20 denier for the core, spun yarn of yarn count Ne60 or Ne80 can be spun using the same California cotton.

Therefore, cotton sheets of yarn count Ne60 or Ne80 which have been woven using higher-grade raw cotton (e.g. Egyptian cotton) becomes possible to be woven with lower-grade California cotton.

The core yarn 1 related to the present invention is easily applicable to both of woven fabric and knitted fabric, and effectively applicable to variety of outerwear as well as underwear because the yarn has the range of yarn count suitable for the clothing products.

Further, although woven fabric related to the present invention uses the core yarn 1 containing polyester monofilament false twist textured yarn as the core 2, only cotton yarn of the sheath exists on the outer surface and therefore the touch and texture-feeling are the same with the cotton yarn of 100% cotton. Therefore, it is also preferably applicable to underwear and sheets which contact with human skin. And since yarn strength is stable for woven and knitted fabric using the core yarn of fine yarn count, it is also applicable to high-grade outer wear. 

1. A core yarn formed of a spun yarn comprising a core formed of filament yarn and sheath formed of staple fiber, wherein said filament yarn consists of single or plural monofilament false twist textured yarn.
 2. The core yarn according to claim 1, wherein said core is formed of an untwisted yarn and wrapped around with staple fiber while staying the untwisted state.
 3. The core yarn according to claim 2, wherein said core is formed of a polyester monofilament false twist textured yarn.
 4. The core yarn according to claim 1, wherein the thickness rate of said core is preferably not more than approximately 20 to 40% of the whole the core yarn, and rate of said sheath is not less than approximately 80 to 60%.
 5. The core yarn according to claim 4, wherein said staple fiber is cotton, said core is a polyester monofilament false twist textured yarn of 20 denier, and a cotton yarn having cotton yarn count Ne20 to Ne100 is spun.
 6. The core yarn according to claim 1, wherein the core yarn is spun by air spinning machine in which fasciated spun yarn is spun while binding around the untwisted core with sheath fiber.
 7. Woven and knitted fabrics woven or knitted using the core yarn according to claim
 1. 8. Woven and knitted fabrics woven or knitted using the core yarn according to claim
 2. 9. Woven and knitted fabrics woven or knitted using the core yarn according to claim
 3. 10. Woven and knitted fabrics woven or knitted using the core yarn according to claim
 4. 11. Woven and knitted fabrics woven or knitted using the core yarn according to claim
 5. 12. Woven and knitted fabrics woven or knitted using the core yarn according to claim
 6. 